1. Field of the Invention.
This invention relates to the field of fluid flow devices, and more particular, to nozzles which generate a laminar discharge of fluid.
2. Prior Art.
It is often desired to utilize a fluid, such as water, as part of a display or attraction. For example, various types of fountains adorn public and private plazas, parks, advertisements, and amusement parks. As part of these displays, it may be desired to produce a smooth, laminar flow of water which gives the appearance of a solid glass or clear plastic rod.
In the past, various methods have been used to provide a laminar stream of water. For example, Wilson, U.S. Pat. No. 2,432,641 discloses a dispensing nozzle which includes a cylindrical member having semicircular channels formed on the inside face for reducing the turbulence of fluids, such as gasoline. Jeffras et al, U.S. Pat. No. 4,393,991, discloses a sonic water jet nozzle which utilizes an elongated conical nozzle which includes fin-like members to reduce the turbulence of the water and to produce a laminar flow of water. Parkison et al, U.S. Pat. No. 3,321,140, discloses an attachment for a faucet which utilizes a series of fins in a cylindrical nozzle for producing a laminar flow of water to reduce the splash on the bottom of a sink or tub. Barker, U.S. Pat. No. 2,054,964, discloses a fluid discharge device which uses a series of parallel plates providing channels parallel to the flow of the fluid to facilitate the discharging of a smooth stream of water. Watts, U.S. Pat. No. 2,408,588, discloses a method of producing columnar flow of an oxidizing gas to be used in dividing or desurfacing metal. Watts utilizes a passage having a cross section which is noncircular, such as eliptical, triangular or square. Parkison, U.S. Pat. No. 3,730,440, teaches a laminar flow spout which utilizes a plurality of independent nozzles arranged within a single spout which results in a plurality of streams having laminar flow characteristics.
Other methods which have been utilized to obtain laminar flow of fluids include the use of curved perforated disks inserted in the nozzle to produce a splashless laminar output, such as in Parkison et al, U.S. Pat. Nos. 3,851,825; Nelson, 3,630,444; and Parkison, 3,730,439. Nel, U.S. Pat. No. 4,119,276, utilizes a plurality of straight, perforated screens having varying degrees of perforation to provide a splash free, clear, laminar output.
Although these prior methods are useful in reducing the amount of turbulence in streams of water, none of the methods is suitable in providing a fountain display in which substantially all of the turbulence is eliminated from a columnar stream of water. One disadvantage of these prior methods is the introduction of turbulence immediately prior to the nozzle. Each method cited above uses axial or radial water intake to the nozzle region. Such a method produces a great deal of turbulence in the fluid just upstream of the nozzle. For example, when an axial intake is used, the water entering the nozzle from the intake is meeting water which is stationary or is moving in a direction opposite that of the intake stream. This creates a turbulence profile at this interface so that the turbulence profile of the water passing through the nozzle region is not uniform. As a result, eddies and turbulences are carried through the nozzle system and result in an output which includes undulations, splashing, and ripples.
Likewise, an axial intake creates a turbulence profile immediately downstream of the nozzle system which is non-uniform. This also introduces unwanted turbulence into the final output stream of water.
Therefore, it is the object of the present invention to provide a means for producing a laminar fluid output stream having substantially no turbulence.
It is a further object on the present invention to provide a means for further providing a laminar output fluid flow nozzle in which fluid having a uniform turbulence profile is presented to the nozzle region.
It is yet another object of the present invention to provide an improved laminar output nozzle.